The long term objective of this proposal is to determine the essential neural structures and neurotransmitters responsible for expression of autonomic and neuroendocrine responses to psychological stress. The amygdala has been implicated in the etiology/expression of hypertension, cardiac arrhythmias and stress-induced gastric ulcers. It is also a site where anti-anxiety drugs act. The specific aims of this proposal are to study the anatomy and function the amygdala, neuropeptides associated autonomic/neuroendocrine neural circuitry. The amygdala contains a high density of calcitonin gene related peptide nerve terminals and receptors. The nerve terminals originate from the parabrachial nucleus which is an important cardiovascular relay center in the brainstem. Previous studies suggest that calcitonin gene related peptide in the amygdala and the brain may be responsible for mediating cardiovascular responses to stress. Experiments are proposed that determine the anatomical circuitry whereby calcitonin gene related peptide interacts with amygdaloid cells and neurons that are connected to autonomic regions of the brainstem. Experiments are also proposed that examine the role of the amygdala and parabrachial nucleus in expression of cardiovascular and neuroendocrine responses to conditioned stress. The data obtained will provide important new information on the role of neuropeptides and associated brain connections in expression of cardiovascular and neuroendocrine responses to stress.